The tracking of high value products and/or products for which control and/or documenting of the location and/or possession of, such as controlled substances, can be expensive. With respect to medical and/or retail marijuana, under current laws and regulations, it can be important to track the final product, and it can also be important to track the plant from planting as a seed or potting as a stem, due to the regulatory laws that involve growing marijuana.
Marijuana plants can be grown from seeds. However, marijuana plants are typically grown from stems rather than seeds. A seed, or a stem taken from a marijuana plant, can be potted, in soil or in water (hydroponic system) in order to prompt the stem to produce roots. As the potted clone grows further, the clone transfers into a vegetative stage. At this stage, the potted plant, or potted clone, is then typically moved to another location repotted. This repotting can occur before, during, or after transportation to the new location, and each clone is typically potted into a bigger pot. After a period of time of further growth, typically 6-7 weeks, the flowering stage begins. At this time, the plants may again be moved to another location. When the plants have matured further, they are harvested. Harvesting typically occurs when the plants reach maximum potential for budding. The harvested materials from multiple plants are then typically gathered and a lot or batch of the harvested material, or product, is created, which will be dried and cured together. The dried and cured product is packaged to be sold.
In certain jurisdictions, people are allowed to purchase marijuana only after receiving authorization for such purchase, and/or are only allowed to purchase marijuana in limited quantities and/or within limited or prescribed time periods. Further, a grower and/or supplier may be allowed to grow and/or supply a limited quantity, such as a limited: number of marijuana plants, volume of marijuana, weight of marijuana, retail value of marijuana, and/or other metric with respect to the marijuana being grown and/or supplied. The grower may have an associated license number, or other identifying information. As an example, in Colorado, the retail sale of marijuana is currently limited to ¼ oz per day per person for non-residents.
RFID (Radio Frequency Identification) technology is an identification technology that is commonly used to identify, track, and/or trace goods, in order to provide security, manage inventory, facilitate a sale or exchange, and/or improve supply chain efficiencies. Such tracking by the RFID system can be automated, such that, for example, the RFID tag is automatically read when positioned in a certain geographic location or is attached to an object that is moved. Radio frequency identification (RFID) technology enables automatic identification of unique items by using radio frequency (RF) signals. A typical RFID system includes a tag, a reader, an antenna, and a host system. The reader gathers information about an object by communicating through the antenna with the tag attached to the object. The host system then processes the data collected by the reader to obtain information related to the tagged object.
There are generally three different types of Radio Frequency Identification (RFID) tags: passive RFID tags, semi-passive RFID tags, and active RFID tags. Passive RFID tags do not contain an on-tag power source. Passive tags harvest all of the tag's operational energy from the RFID reader's communication signal and use this harvested power to send back a signal with the information on the tag. Semi-passive RFID tags, which are also called battery assisted (BAP) tags have an on-tag power source, and also use energy harvested from the reader's communication signal. Active RFID tags have an on-tag power source, and use this on-tag power source to actively generate and transmit an electromagnetic signal in response to receipt of the RFID reader's signal and perform other functions.
Battery-less tags, by virtue of their potentially ultra-low cost and essentially unlimited shelf life, are important components for a broad class of important RFID applications. When an RFID inventory-tracking scheme requires every case or item within the purview of an inventory-control system to be tagged, which is the typical case for retail-distribution applications battery-less tags are generally preferred. When long-term storage of tagged items is involved, such as in a physical records archive managed with RFID technology, the finite shelf-life of batteries is an additional strong motivator for the use of battery-less tags.
Poor performance for RFID systems are still frequently experienced when tags are on or near items that contain or comprise materials that interact strongly with RF propagation. Such materials include metal, dielectrics and lossy dielectrics that reflect, refract or attenuate RF energy incident on them or passing through them. Cans, foils, liquids, gels, dense powders, produce, meat and dairy products are just a few examples among numerous items that can severely impair the RF coupling between a reader and a tag.
Severe attenuation of a signal propagating from an RFID reader to a battery-less RFID tag is particularly problematic. The RF electromagnetic field strength required to operate a battery-less RFID tag is significantly higher than that required to communicate to an electronic receiver having an independent power supply such as a battery. Active electronic circuitry, powered by a battery or other power source, can indeed detect, decode and otherwise process extremely weak signals. A battery-less RFID tag, however, cannot operate such electronic circuitry until the tag has extracted sufficient energy from the RF electromagnetic field supplied by the reader or another external source. The incident RF field level required to provide operating power for the electronic circuitry is far greater than that required to communicate with already-powered circuits. The frequent difficulty in achieving the necessary incident RF field strength in the presence of material configurations with adverse RF propagation characteristics, while still satisfying regulatory constraints on radiated RF power levels, is an important issue.
Except providing longer read ranges by powering up the RF chip without any signal from the interrogator in the case of active tags, the battery in the tags are commonly used to power up the circuitry of the tags that has additional features and components such as an extended memory, a real time clock, and/or one or more sensors.